Tag Archives: FLSMIDTH (PTY) LTD


In pride of place on the FLSmidth Electra Mining Africa exhibition stand this year will be a 1:20 scale model of its REFLUX™ Classifier (RC) modular plant, representing – in more ways than one – the future of processing in the mining sector.

According to FLSmidth Commercial Manager Terence Osborn, the RC plant is a good example of an integrated solution designed to a meet a customer’s tailings-related risks and requirements.

“The plant demonstrates how our insights and expertise make us more than an equipment supplier,” says Osborn. “Our focus is to bring the value of our technical knowledge base – along with our range of advanced product offerings – directly to bear on improving customers’ sustainability and profitability.”

The RC plant embodies FLSmidth’s leading technologies as well as its innovative business approach. Equipped with advanced automation facilities, a full-size version of this plant is in operation for a mining customer on an outcomes-based toll treatment, model. It treats waste product, or tailings, and recovers valuable minerals as a saleable product for the customer, without adding extra workload or risk to their operation.

FLSmidth’s technical advancement in automation and digitalization is vital in making these solutions more valuable; both FLSmidth and the customer can observe and assess the key operational parameters of the plant in real-time in their respective head offices anywhere in the world. He emphasised how much of a priority this direction was for the business.

“Our appointment in May this year of a Chief Digital Officer at global group executive level reflects our focus on digital efforts to leverage solutions,” he says. “This is key to our corporate strategy going forward and customers will see increasing levels of bottom line benefit arising from this direction.”

Osborn emphasises that Electra Mining Africa is a good opportunity to engage with operations-level customers, listening to feedback and sharing ideas about the kind of solutions that help them achieve their goals and targets.

“Our role is increasingly to provide total solutions that package our expertise and equipment for the customer’s benefit – and to make it possible for them to run efficient plants with high recoveries,” he says. “This includes our ability to effectively integrate equipment and solutions into their existing infrastructure.”


Finding the optimal design and delivery solution for a large thickener at a remote gold mine in the West African state of Mauritania meant considering a complex range of technical, transportation and assembly options, according to FLSmidth senior account manager Ricus van Reenen.

The cost of transporting the components for the 50-metre diameter thickener was a key factor affecting the design, says van Reenen. He highlights that transportation of components to remote sites can comprise a substantial portion of costs, and that break-bulk shipping costs are significantly higher than containerised transport.

“Given that the thickener components needed to be shipped by sea as well as by road, containers were considered the most economical mode solution,” he says. “This requires that the plate sections be cut and rolled in dimensions that can be packed into containers for shipping to site.
The structural support sections like the I-beams will be fabricated to final stage at our facility and just bolted on site, but the plates will need to then be welded by expert welders.”

While bolted thickeners are often more economical to construct, as they obviate the need for extensive on-site welding, this option cannot easily be applied to thickeners larger than 50 metres in diameter.

“For these larger designs, the support structure is erected on site followed by the welding together of the plate sections from one end to the other,” he says. “After the plate sections have been welded to the structure, the welds are sandblasted, primed and applied with a final paint coating over the welded areas.”

Certain cost-saving strategies can still be employed in these situations; for instance, the plates can be painted before shipping with the weld-strips left clean to facilitate on-site welding.

Van Reenen emphasises the importance of the documented assembly procedure – according to FLSmidth’s global best practice – that is applied when erecting these large thickeners.

“When supplying a thickener, part of our engineering deliverables includes an installation methodology for the site contractor to follow, to make sure that they implement each stage correctly,” he says. “FLSmidth also provides a technical installation expert from the most suitable of our global offices who visits the site at appropriate intervals to advise and inspect.”

He further emphasises that the forces demanded within large thickeners also makes the choice of gearbox drive much more important.

“Smaller thickeners can usually be designed with planetary gearbox drives – available from a number of OEMs,” he says. “With really large drives requiring higher torque, however, we prefer to use our own ring-gear Dorr Oliver drives which can reach much higher torque values than planetary drives.
The ring-gear drives are also more able to handle axial and radial loadings on the rakes.”


As the fines recovery gains achieved by REFLUX™ Classification (RC™) technology are extended to a wider range of commodities, FLSmidth is making mines an offer they can’t refuse: to share the value of expanded production – including retreatment of waste dumps – at no cost to themselves.

The profit-share option is one of a range of contractual and financial alternatives that the leading engineering Original Equipment Manufacturer (OEM) is putting on the table as part of its commitment to sustainable productivity for its customers, according to FLSmidth’s capital sales director for sub-Saharan Africa, Roy Hazell.

“We are putting our money where our mouth is– this is how confident we are in this technology,” says Hazell. “We can even operate the plant on the customer’s behalf; no‑one knows our equipment better than we do and we can ensure that it performs to expectation.”

Other options for customers include a toll treatment arrangement, while some customers may prefer to purchase the solution outright and operate it themselves as a standalone unit to augment production levels.

He says the modular RC solution is ideal for any mining company that has dumps or stockpiles of fines where they would like to recover minerals, but where the quantities do not justify the building of a dedicated fixed plant. The modular format allows a short term treatment plant of capacities around 100 tph to be set up without disrupting any existing process facilities. At the same time, the modular format can even be expanded for customers who want production capacity up to 400 to 600 tph although these plants are more likely to a fixed solution.

The sector is recognising that the RC concept offers better recovery rates than spirals when dealing with fine particles, more effectively separating materials of different densities. With one modular RC plant already commissioned and in ramp-up and optimisation phase at a platinum mine near Rustenburg, FLSmidth is developing these plants for coal fines and will take the modular concept to other commodities such as gold.

PGM producers have gained particular value from RC technology in terms of recovering chromite – a contaminant in PGM concentrate – as an added source of revenue.


The concept of bolted thickeners is growing in popularity. According to FLSmidth senior account manager Ricus van Reenen, this is a fit-for-purpose, high quality dewatering solution with reduced project construction risk and duration.

These benefits resulted in FLSmidth securing an order in July 2017 for a 24 metre diameter high-rate thickener from a South African iron ore mining company.

“Although this concept has been around for at least a decade, it is becoming more commonly used,” says van Reenen. “With a bolted tank, the whole thickener is constructed inside a purpose-designed fabrication facility with all welding, sandblasting and painting taking place under controlled conditions. This guarantees that everything fits as it should so there are no unexpected delays on site.”

Thickeners have traditionally been constructed on site; all rolled and bent plates are transported to the required location where they are welded onto the prefabricated support structure and radial beams.

“This process can take weeks to complete, as there are kilometres of welding runs required,” he says. “Moreover, the considerable weight of the material in the finished tank – several thousand tonnes – means that the weld quality needs to be high and coded welders must conduct the work.”

These welders often have to be accommodated on site for extended periods of time, which adds to the cost; cross-border work often involves the added burden of obtaining work permits and special visas for these workers.

Sandblasting of the welding runs is then necessary, as well as a final coat of paint. In addition to the extra costs, the work is highly weather dependent and delays can be caused by rain or excessive dust.

“Weather related delays can cause time over-runs for the contractor, which can then lead to penalty costs,” he says. “This sort of project risk is one of the main reasons why contractors are choosing bolted thickeners. As a contractor, your time on site is where your most significant risk will lie.”

After the construction of a bolted thickener in a workshop, the whole tank can be transported to site where the bulk of the on-site work can be undertaken by a mechanical supervisor, who oversees the lifting and placement with the support of a rigger and a crane driver. Local labour can be used to fit the necessary bolts into the structure, and a technical specialist can come in to torque the bolts.

“Once in place, only touch-up painting is required, so poor weather won’t be a serious risk factor,” says van Reenen. “Ensuring that deadlines are met means on-time commissioning, which aligns well with FLSmidth’s role as productivity partner to mining projects.”

He notes that FLSmidth has supplied at least 20 projects globally with bolted thickener tanks, putting close to 40 of these units into the market in recent years. The largest unit was a 45 metre diameter high-rate thickener, while the more specialised deep cone thickeners have also been built in this way up to a size of 35 metres in diameter.